CNOOC's fracturing equipment technical capabilities make another breakthrough

　　On July 13, the reporter learned from the Engineering Technology Operation Center of CNOOC Tianjin Branch that after the implementation of the offshore low-permeability fracturing technology in the two new wells in Bozhong 25-1 oilfield, the production increased by nearly 2 times.
The development strategy of "fracturing to ensure initial production, and energy supplementation to maintain stable production" has been initially realized, and it has also provided further project experience and technical accumulation for overcoming China's offshore low-permeability fracturing development problems
.

　　China has abundant proven reserves of offshore low-permeability crude oil, which is an important source of potential reserves for domestic oil and gas reserves and production
.
Such reservoirs are deeply buried, low in permeability, difficult to flow oil and gas, low in natural productivity of a single well, short in cumulative development time, difficult in development, and difficult to achieve economical production
.

　　Fracturing is an important stimulation measure to transform low-permeability oil and gas reservoirs.
By artificially creating reservoir fractures, it can improve the oil flow environment in the ground and increase the production of oil wells, which is equivalent to building a "highway" for oil and gas flow underground
.
However, limited by the size of the offshore platform, load capacity, and transportation conditions, the fracturing and development of offshore oil and gas reservoirs is difficult
.
In 2006, CNOOC carried out offshore fracturing operations.
However, due to the low-permeability fracturing for a long time, the scale has been small and the reconstruction was limited, resulting in unstable production results, and a large amount of low-permeability reserves are still unutilized underground
.

The picture shows the employees of the Engineering Technology Operation Center of CNOOC Tianjin Branch working on fracturing operations
.
(Photo courtesy of the company)

　　In order to achieve the goal of offshore low-permeability fracturing in the “Seven-Year Action Plan” to increase domestic oil and gas reserves and production, since 2019, CNOOC has been pressing the “fast-forward button” for low-permeability fracturing, gradually possessing mature The operational capabilities of single-layer or multi-layer fracturing in vertical wells, directional wells, and staged fracturing in large-scale horizontal wells, and the full-chain fracturing technical service capabilities from reservoir analysis, process design, field construction, and post-fracturing effect evaluation.
A series of fracturing technologies for offshore low-permeability reservoirs, such as packer sliding-sleeve fracturing technology, deflagration fracturing technology, acid fracturing technology, etc.
, as well as supporting technologies such as continuous mixing and flow-back fluid treatment, are used for offshore low-permeability reservoirs.
The economic and effective development of seepage oil field has created conditions
.

　　This fracturing operation is a major review of the technical capabilities of CNOOC's fracturing equipment
.
During the operation, the fracturing team adopted localized equipment from the high-power sand control pump set on the ground, the sand mixing truck, the data mining room and the high-pressure pipeline, to the key equipment and tools such as the downhole sand control tool and packer, and got rid of the long-term concern for the sand control tool.
Dependence on foreign equipment and downhole tools
.
At the same time, using the high-temperature seawater-based fracturing fluid system developed by CNOOC for 3 years, the viscosity can reach 80% of the final viscosity within 5 minutes, which improves the timeliness of offshore fracturing operations
.
In addition, the fracturing team thoroughly implemented the concept of integration, weakened professional and institutional boundaries, actively cultivated low-permeability and high-yield wells, and released production capacity five days ahead of schedule
.

　　In the next step, CNOOC will promote the formation of a large-scale offshore low-permeability fracturing technology system by taking the road of integrated innovation and development of multi-disciplinary integration and multi-technology integration, and inject strength into the efficient development of offshore low-permeability oilfields
.